Minimwatch stopped working immediately as scanning was completed

[simoncn]

Which Synology model is it? Different models have different implementations for sleeping.

Please try entering http://x.x.x.x:9790 into a web browser when the icon is grey. Do you see the MinimServer status page and does the icon change to green? If both of these happen, the issue is probably related to the NAS sleeping. If you see the page but the icon stays grey, it is probably a multicast discovery issue with your network (see this section).

MinimServer uses ohNet for UPnP communication. ohNet doesn't have any way to do a "UPnP blast/keep alive" as the ohNet developers think the resulting increased network traffic is harmful to the network and is not needed if the network is working correctly.